Runtime directories: in package or by scripts?

[Игорь Пашев <pashev.igor@gmail.com>]

I'm creating packages with programs which use some directories for
persistent data.
E. g. dladm will use /etc/dladm to save data in.

What is the best way to ship such a diretory:
in package (d/foo.dirs) or create in postinst script?